Nonvolative memory cells programable by phase change

摘要

An array of memory cells, each cell comprising a first and second ferromagnetic layers that form either a spin valve or a magnetic tunnel junction; at least one conductor operatively connected to at least one of the first and second ferromagnetic layers; a third ferromagnetic layer magnetically coupled to the second magnetic layer having permittivity which changes from a first state to a second state of lower permittivity upon heating; the second ferromagnetic layer being influenced by the permittivity of the third ferromagnetic layer; and a heater element operatively associated with the third magnetic layer which selectively provides heat to the third magnetic layer to change its permittivity. An alternate embodiment comprises an array of cells, each cell comprising a ferromagnetic region having permittivity which changes from a first state to a second state upon heating and a heater operatively which selectively provides heat to the third magnetic layer.

主权项

1. A memory device comprising an array of cells, each cell comprising:
a first ferromagnetic layer with a fixed magnetic polarity; a second ferromagnetic layer with a magnetic polarity modifiable by a spin torque transfer current; at least one conductor operatively connected to the first and second ferromagnetic layers; a barrier layer between the first and second ferromagnetic layers forming a magnetic tunnel junction; a third ferromagnetic layer magnetically coupled to the second magnetic layer; the third magnetic layer having tunable permittivity; a heater element operatively associated with the third magnetic layer which selectively provides heat to the third ferromagnetic layer; the third ferromagnetic layer having a first permeable amorphous state; the third ferromagnetic layer capable of being heated to a second state which is crystalline to thereby decrease the permittivity of the third magnetic layer; whereby changes in the permittivity of the third magnetic layer effect the response of the second ferromagnetic layer to a spin polarized current.